Old line, non-Twittering food vendors hate seeing these usurpers on their turf. Cue the death threats. The operator of the Twittering cart "Schnitzel and Things" told Midtown Lunch about a bad scene in Madison Square Park the other day: "We got harassed by 4 different dudes as soon as we showed up... I called the cops on them for harassment. Then they brought their own cop... Once they started to threaten our lives, we got a bit aggressive." Twitter gangs can't be far behind. What's the point of microblogging if you can't use it to call for backup?